Meanwhile in Baltimore, Bloomberg headlined a summit on guns at the Johns Hopkins Bloomberg School of Public Health. During a speech Monday morning, he charged that Congress has “systematically denied the American people access to information about guns and gun violence.”

“Most egregiously and outrageously, Congress has severely restricted the scientists at the Centers for Disease Control and Prevention from studying the epidemic of gun violence and they put similar restrictions on the scientists at the National Institutes of Health,” Bloomberg said. “Congress has no business dictating what public health issues scientists can and should study. What are they afraid of?”

When elected officials try to “muzzle scientific research and bury the truth,” the mayor said, “they make our society less free and less safe.”

Bloomberg has been an outspoken voice against illegal guns since 2006, at the start of his second term at City Hall, when he launched a coalition of mayors around the country to combat gun violence, largely bankrolled by his personal fortune.